Process of preparing curable compositions and compositions therefrom

ABSTRACT

The invention relates to a curable composition and a process of preparing the curable composition. The process comprises (a) forming an oligomer from oligomerization of a mixture of a monomer A having a functional group and a monomer B at a temperature in the range of from 150° C. to 650° C., a pressure in the range of from 3 MPa to 35 MPa and the pressure is high enough to maintain the reaction mixture in a fluid state and a residence time in the range of from 0.1 second to 4 minutes; and (b) reacting a modifier having at least one reactive moiety with the oligomer through a reaction between the reactive moiety of the modifier and the functional group of the monomer A in the oligomer, and the modifier further comprises a curable group.

[0001] The present invention relates to a process of preparing curablecompositions and compositions therefrom.

[0002] Oligomers, polymers with low Dp (degree of polymerization), ofacrylate or methacrylate unit-containing backbones are of commercialinterest and have industrial uses for many different applications, suchas adhesives, inks, coatings, films, and others. A suitable low Dp valuewill provide a material with a molecular weight high enough for reducedtoxicity, yet low enough for low viscosity. However, production of sucholigomers has proven to be difficult and is frequently carried out bycumbersome and/or not very selective processes. It becomes even moredifficult if a crosslinkable or curable oligomer composition is desiredfor the applications. This is because crosslinking or curing propertytypically requires the presence of additional reactive pendant groups inthe oligomers. Such reactive pendant groups may be partially orsubstantially eliminated or reacted away by unintended side reactions orpremature crosslinking reactions during the oligomerization reaction.

[0003] Several approaches have been tried and used to effect productionof such oligomers. For example, one approach uses chain transfer agentsto control Dp. As a result of the chain transfer chemistry involved, onechain transfer agent is incorporated into each backbone structure of theoligomers. This makes the oligomer property much less uniform and harderto control. In addition, the most commonly used chain transfer agentsare mercaptans. Due to their odors and chemical properties, it becomesincreasingly more difficult socially and less acceptable environmentallyto use such sulfur-based materials. Other common chain transfer agentssuch as hypophosphites, bisulfites and alcohols would also impartadditional functionalities into the oligomers. Such additionalfunctionalities may not be compatible with other ingredients in aformulated product or suitable for the intended applications. Removal ofthe additional functionality from the resultant oligomers may bedifficult and/or expensive.

[0004] Another approach calls for the use of large amounts of initiatorsor catalysts. This approach adds raw material cost to oligomerproduction. It also may result in undesirable oligomer chaindegradations, branching, and unintended or premature crosslinking of theproduct prior to use. In addition, any residual initiators or catalystsin the product may have to be removed before the product can be used formany applications to avoid compatibility or contamination problems.

[0005] U.S. Pat. No. 4,356,288, discloses the preparation ofterminally-unsaturated oligomers with a Dp in the range of from about 6to about 30 from esters of acrylic acid by an anionic polymerizationreaction carried out in the presence of a catalytic amount of analkoxide anion. Alkoxide anions are known to be sensitive to water.Accordingly, the method is often adversely affected by the presence ofmoisture, resulting in lower yield and/or lower uniformity of theoligomer product.

[0006] Another patent, U.S. Pat. No. 5,710,227, discloses a hightemperature, continuous polymerization process for preparing terminallyunsaturated oligomers which are formed from acrylic acid and its salts,and acrylic acid and its salts with other ethylenically unsaturatedmonomers. The high temperature, continuous polymerization process solvesmany of the problems associated with previously known methods forpreparing terminally-unsaturated oligomers formed from acrylic acid.However, the neat form of many of the acrylic acid products are solid atroom temperature and, thus, requiring either heating and/or the additionof a solvent to handle and use the products.

[0007] U.S. Pat. No. 5,484,850 discloses copolymer compositions whichare crosslinkable by a free radical method and have a Mn from 1500 to6000 and a polydispersity of 1 to 4. Copolymer A is composed of from 50to 85 mol% of a monomer (a1) containing methacryloyl group; from 15 mol%to 50 mol% of another monomer (a2) capable of undergoing free-radicalpolymerization; and from 5 mol% to 50 mol% of the total amount of themonomers (a1) and (a2) being monomers (a3) which carry functional groupsselected from the group consisting of hydroxy, carboxyamido, amino,carbonyl, isocyanate, carboxyl and epoxy, the functional groups beingcapable of undergoing a condensation or addition reaction. Thepolymerization is carried out at a temperature from 140 to 210° C. andwith an average residence time of from 2 minutes to 90 minutes.Copolymer A reacts with an olefinically unsaturated monomer B whichcarries a functional group which is complementary to the functionalgroups of monomers (a3). The products are solids which tend to limittheir uses and processing options.

[0008] The present invention seeks to overcome the problems associatedwith the previously disclosed methods for preparing oligomers,particularly curable or crosslinkable liquid oligomers, by providing anoligomerization process that produces curable oligomers with a low Dp,in the range of from 3 to 100, without the need of excessive amounts ofinitiators. The curable oligomer products are in liquid form and may beterminally unsaturated. The crosslinkable or curable functionality isincorporated into the oligomer by a reaction after the oligomerization—apost-oligomerization reaction—between the oligomer or altered oligomerwith a modifier which contains a crosslinkable/curable functional group.The present invention also provides curable oligomer compositionsprepared according to the disclosed process. Furthermore, the inventionprovides curable oligomer compositions which are substantially free ofmetals, salts and/or surfactant contaminants. The product from thepresent invention is useful for a number of applications, such as films,markings, coatings, paints, adhesives, binders, inks and others.

[0009] More specifically, the present invention relates to a process ofpreparing a curable composition comprising forming an oligomer having aDp in the range of from 3 to 100 from oligomerization of a mixture whichcomprises a monomer A and a monomer B under a first condition, whereinthe monomer A has at least one functional group which either isgenerated after the oligomerization or is present in the monomer Abefore the oligomerization and remains substantially unreacted duringthe oligomerization; the oligomer has a first number of monomer unitsincorporated into its backbone; and wherein the first conditioncomprises a temperature in the range of from 150° C. to 650° C. and apressure in the range of from 3 MPa to 35 MPa which is sufficient tomaintain the mixture in a fluid state, and a residence time at thetemperature and the pressure in the range of from 0.1 second to 4minutes; and reacting a modifier having at least one reactive moietywith the oligomer through a reaction under a second condition betweenthe reactive moiety of the modifier and the functional group of themonomer A incorporated into the oligomer to produce the curablecomposition, wherein the modifier further comprises a curable groupselected from the group consisting of a carbon-carbon double bond, anoxygen-containing heterocyclic group and mixtures thereof, and thecurable group remains pendant in the curable composition andcrosslinkable after the reaction.

[0010] The term “oligomerz” used herein means a polymer compositionwhich has a degree of polymerization (Dp) in the range of from 3 to 100.Unless otherwise specified in the present application, the term“polymerization” is used herein as a generic term and interchangeablywith the term “oligomerization.” An oligomer has a number of monomerunits incorporated into the backbone. Dp is determined as a monomer unitaverage number. Depending on the oligomerization reaction mechanism, theactual number of carbon atoms in a particular oligomer backbone may beof an even or an odd number, even though the carbon-carbon double bondsin the monomers have two carbons each. Since it is rare that all of theoligomer molecules have the same total number of monomer unitsincorporated into the backbone, there is usually a distribution ofvarious oligomers with either smaller and/or larger Dp than the rangeindicated and/or preferred in the application. This type of distributionis also known to exist in almost all polymers and it is commonlyreferred to as “polydispersity.” A preferred Dp for this invention is inthe range of from 5 to 50. A more preferred Dp is in the range of from 5to 20.

[0011] The present invention also relates to a curable composition,particularly by UV, visible light, electron beam methods, prepared by aprocess comprising forming an oligomer with a Dp in the range of from 3to 100 from oligomerization of a mixture which comprises a monomer A anda monomer B under a first condition, wherein the monomer A has at leastone functional group which either is generated after the oligomerizationor is present in the monomer A before the oligomerization and remainssubstantially unreacted during the oligomerization; wherein the monomerB is selected from the group consisting of ethylene, propylene, C₄ toC₁₀ α-olefins, butadiene, isoprene, styrene, substituted styrene, vinylester, vinyl ether, vinyl silane, vinyl halide, acrylic acid,methacrylic acid, crotonic acid, alkyl acrylate ester, alkylmethacrylate ester, alkyl crotonate ester, acrylamide, methacrylamide,N-subsituted acrylamide, N-substituted methacrylamide and mixturesthereof; the oligomer has a first number of monomer units incorporatedinto its backbone; and wherein the first condition comprises atemperature in the range of from 150° C. to 650° C. and a pressure inthe range of from 3 MPa to 35 MPa which is sufficient to maintain themixture in a fluid state, and a residence time at the temperature andthe pressure in the range of from 0.1 second to 4 minutes; and reactinga modifier having at least one reactive moiety with the oligomer througha reaction under a second condition between the reactive moiety of themodifier and the functional group of the monomer A incorporated into theoligomer to produce the curable composition, wherein the modifierfurther comprises a curable group selected from the group consisting ofa carbon-carbon double bond, an oxygen-containing heterocyclic group andmixtures thereof, and the curable group remains pendant in the curablecomposition and crosslinkable after the reaction.

[0012] The word “pendant” means that a group, a functional group or areactive moiety, is not in the backbone structure itself of an oligomeror polymer. A reaction of a pendant group for the present invention willnot cause any changes of the backbone structure itself. A pendant group,may be attached directly to a carbon in the backbone structure of theoligomer. Examples of this directly-attached type pendant groups include—OH or —OC(═O)(CH₃) group (from vinyl acetate monomer); and —COOH or—COO(R) group (from acrylates or methacrylates). Or, there may be otherintermediate chemical moieties or groups between the functional groupand the carbon atom in the backbone structure to server as “linkers.” Anexample of this type is the —OH group in 2-hydroxyethyl methacrylatewhen it is used as one of the monomers. There is a —CH₂CH₂— groupbetween the —OH group and the —C(═O)—O— group of the backbone structure.Other linker examples include (—O—CH₂CH₂—)_(n) where n is in the rangeof 1 to 10. Others become clear from the rest of the description of thepresent invention. Pendant groups for this invention are generallyreactive, either they are suitable for attaching a crosslinkable orcurable group to the oligomers, or they are used for curing orcrosslinking. Curing and crosslinking are used herein interchangeably.

[0013] To facilitate understanding of the present invention, a generalscheme is summarized below. It is used for illustration purposes only,not intended for limiting the scope of invention which is defined hereinby the specification and the claims. It is also understood that some ofthe steps may be carried out simultaneously or sequentially. monomerA+monomer B→oligomer[→post-oligomerization generation of functionalgroups, optional]→reaction with a modifier to form a curable composition[→emulsion formation to form a curable formulation, optional]→curing orcrosslinking.

[0014] In the instant invention, an oligomer is prepared by anoligomerization reaction of a mixture which comprises a monomer A and amonomer B. The mixture may further comprise a solvent and othermaterials for a variety of purposes such as catalysis or reactionmediation. The monomer A and the monomer B preferably are different, butthey may be the same in certain specific cases wherein the monomer A isproduced by transforming the monomer B incorporated in an oligomer afterthe oligomerization reaction, as described below in more detail. Themonomer A and the monomer B may be premixed, with or without a solvent,prior to the oligomerization, or they may be introduced separately intoa reaction zone at a predetermined rate or manner. The latter typicallyrequires a mechanism to provide proper mixing. The mechanism can bestatic such as specially designed inlets, nozzles, or mobile such as amechanical stirring device. For the present invention, it is preferredto have the monomers and optionally a solvent, if present, premixedbefore they are fed into the reactor.

[0015] For the present invention, the monomer A must have, in additionto a polymerizable or oligomerizable carbon-carbon double bond, afunctional group which does not participate in, or remains pendant orsubstantially unreacted during the oligomerization reaction. Such afunctional group may be already present in the monomer A itself prior tothe oligomerization or it may be generated after the oligomerizationfrom a “monomer A equivalent.” After the functional group is generated,the reaction between the modifier through its reactive moiety and thefunctional group of the oligomer can be carried out to form the curablecomposition.

[0016] It is within the scope of the present invention to generate thefunctional group post-oligomerization from a “monomer A equivalent”,i.e. after the oligomerization is completed or substantially completed.This requires the use of a “monomer A equivalent” in the oligomerizationreaction and at least one additional conversion reaction to generate thedesired functional group. It is also possible to have the additionalconversion reaction and the oligomerization occur almost simultaneously.

[0017] A “monomer A equivalent” is an oligomerizable or polymerizablemonomeric carbon-carbon-double-bond-containing compound which hasanother group that may be converted to produce the desired functionalgroup after the oligomerization or polymerization is completed orsubstantially completed during the oligomerization reaction. A “monomerA equivalent” may be the same as the monomer B used in theoligomerization reaction.

[0018] There may be various reasons and benefits for using a “monomer Aequivalent.” For example, vinyl alcohol does not have a chemicallystable monomeric form which can be easily used in an oligomerization orpolymerization reaction. Accordingly, vinyl acetate is used mostfrequently as vinyl alcohol's “equivalent” and the acetate group isconverted by hydrolysis to generate the desired hydroxy (OH) group afterthe oligomerization or polymerization reaction is completed. If desired,the acetate group can also be converted into an acrylate or methacrylategroup via a trans-esterification reaction or by hydrolysis followed bydirect esterification.

[0019] Following is another example of this type of post-oligomerizationgeneration of functional groups, particular pendant functional groups,where the “monomer A equivalent” is the same as the monomer B. Forinstance, a homo-oligomer of methyl acrylate may be partially orcompletely hydrolyzed to form carboxylic acid groups, i.e. —COOMe groupsare transformed into —COOH functional groups via hydrolysis. Suchfunctional groups then can be reacted with a modifier having a reactivemoiety such as glycidyl (meth)acrylate or hydroxyalkyl ester of acrylicor methacrylic acid to achieve the desired incorporation ofcrosslinkable or curable carbon-carbon double bonds. Another exampleinvolves a co-oligomer prepared from different esters of ethylenicallyunsaturated acids. A typical co-oligomer may be made from methylacrylate and n-butyl methacrylate. A post-oligomerization hydrolysisreaction will also produce —COOH groups. One advantage of such apost-oligomerization generation of functional groups is that thehydrolysis reaction can be controlled or adjusted to give the desiredlevel or amount of functional groups in the oligomer products. Becausedifferent monomer units in the oligomer structure usually have differenthydrolysis or trans-esterification rates, this method provides anotherway of controlling the incorporation of crosslinkable functionalities.Another type of post-oligomerization generation of functional groupsinvolves hydrolysis of pendant amide groups.

[0020] Many compounds are suitable for use as the monomer A in thepresent invention. The selection depends primarily on the monomer B usedand the reactive moiety on the selected modifier. The monomer A musthave at least one functional group that exists after or does notsubstantially participate in the oligomerization reaction. Generalcategories of such functional groups include carbon-carbon double bond,halide, hydroxyalkyl, hydroxyaryl, carboxylic acid or ester, epoxy (oroxiranyl), oxetanyl, anhydride, alkylsiloxy, alkoxysilyl, and arylsiloxygroups. Groups like anhydride could be in a form incorporated throughthe carbon-carbon double bond of monomers like maleic anhydride,citraconic anhydride, and itaconic anhydride. It is understood that notall the disclosed functional groups can be used for all the differenttypes of oligomerization reactions. It is also understood that not allthe functional groups will react with all the reactive moieties of allmodifiers. For the present invention, there must be a reasonablereaction rate between the functional group and the reactive moiety undera second reaction condition, with or without a catalyst or reactionmediator. Chemical compatibility must also be satisfied. Specificlimitations on functional groups and reactive moieties are furtherdisclosed herein.

[0021] Examples of a monomer A suitable for the present inventioninclude: acrylic acid, methacrylic acid, 1,3-butadiene, isoprene,4-vinylcyclohexene, allyl alcohol, allyl esters such as allyl acetate,allyl propionate, allyl acrylate, allyl methacrylate, allyl crotonate,vinyl acrylate, vinyl methacrylate, vinyl crotonate, vinyl chloride,vinyl bromide, vinylidene chloride, vinylidene fluoride, vinyl acetate,vinyl benzoate, norbornadiene, substituted norbornadienes,4-vinylcyclohexene oxide, glycidyl methacrylate, glycidyl acrylate,glycidyl crotonate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate,4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropylmethacrylate, 4-hydroxybutyl methacrylate, acrolein, methacrolein,maleic anhydride, itaconic anhydride, citraconic anhydride,vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane,allyltrichlorosilane, allyltrimethoxysilane, allyltriethoxysilane,γ-methacryloxypropyltrimethoxysilane, and mixtures thereof.

[0022] Examples of a “monomer A equivalent” include vinyl acetate, vinylhalide (such as vinyl chloride, vinyl bromide, vinyl iodide, vinylfluoride), vinylidene halide, allyl acetate, allyl propionate,methacrylonitrile, acrylonitrile, C₁—C₂₀ alkyl acrylate esters, C₁—C₂₀alkyl methacrylate esters, C₁—C₂₀ alkyl crotonate esters, acrylamide andN-substituted acrylamides such as N-methylacrylamide, methacrylamide andN-substituted methacrylamides such as N,N-dimethylmethacrylamide, andmixtures thereof. The corresponding functional groups generated are —OH(vinyl acetate and allyl acetate) and —COOH (others) respectively.Depending on the desired products, certain monomer A such as maleicanhydride, itaconic anhydride and citraconic anhydride also could serveas a “monomer A equivalent” to produce dicarboxylic acid functionalgroups.

[0023] The monomer B is typically an ethylenically unsaturated monomerand its derivatives thereof, such as olefins, styrenes, unsaturatedcarboxylic acids, esters and amides, vinyl esters, vinyl ethers, vinylsilanes, and mixtures thereof A preferred monomer B comprisesα,β-ethylenically unsaturated carboxylic acids, preferably acrylic acidand methacrylic acid, and their esters of linear or branched alcoholscontaining from 1 to 20 carbons. Specific examples of monomer B include,but are not necessarily limited to, ethylene, propylene, C₄—C₁₀α-olefins, 1,3-butadiene, isoprene, styrene, substituted styrenes suchas p-methylstyrene, vinyl acetate, vinyl benzoate, vinyl chloride, vinylbromide, allyl acetate, methyl acrylate, methyl methacrylate, methylcrotonate, ethyl acrylate, ethyl methacrylate, ethyl crotonate, n-propylacrylate, n-propyl methacrylate, n-propyl crotonate, i-propyl acrylate,i-propyl methacrylate, i-propyl crotonate, n-butyl acrylate, n-butylmethacrylate, n-butyl crotonate, sec-butyl acrylate, sec-butylmethacrylate, sec-butyl crotonate, ethyl 4,4,4-trifluorocrotonate,2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexylcrotonate, acrylic acid, methacrylic acid, crotonic acid, acrylamide,methacrylamide, N,N-dimethylacrylamide, N,N-diethylmethacrylamide,N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, ethyl vinylether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether,2-ethylhexylvinyl vinyl ether, 2-chloroethyl vinyl ether,2-aminoisobutyl vinyl ether, vinyltrimethylsiane and mixtures thereof.

[0024] Where the desired functional groups are already present in themonomer A and remain substantially unreacted or pendant during and afterthe oligomerization, the molar ratio of the monomer A to monomer Bincorporated into the backbone of the oligomer produced is in the rangeof from 1:40 to 40:1, preferably in the range of from 1:20 to 20:1, mostpreferably in the range of from 1:5 to 5:1.

[0025] Where the functional groups are generated post-oligomerizationfrom the “monomer A equivalent” incorporated into the oligomers, theratio of the number of generated functional groups to the number oftotal monomer units in the oligomer backbone is in the range of from1:100 to 1:1. It is also within the scope of the present invention ifthe “monomer A equivalent” can be converted into more than onefunctional group, say z number of groups, per monomer unit, the ratiocould exceed 1:1 to as high as z:1. For example, if a monomer has amaleic anhydride group which can be converted into two carboxylicfunctional group per monomer unit. The ratio could exceed 1:1 to 1.5:1or to a maximum of 2:1.

[0026] The oligomerization reaction is carried out under a firstcondition which comprises a temperature of at least 150° C., generallyin the range from 150° C. to 650° C., preferably in the range of from200° C. to 500° C., more preferably from 275° C. to 450° C. and apressure in the range of from 3 MPa to 35 MPa, preferably in the rangeof from 20 MPa to 30 MPa. A preferred combination of temperature andpressure is in the ranges of 150° C. to 400° C. and 16 MPa to 32 MParespectively. A more preferred combination of temperature and pressureis in the ranges of 180° C. to 350° C. and 20 MPa to 27 MParespectively. At a given temperature, it is most preferred to use apressure high enough to maintain the reaction mixture at the reactiontemperature, with or without a solvent, in a fluid state-typically aliquid state or a supercritical fluid state. While a completely fluidstate, either liquid or supercritical, is preferred, it is within thescope of the present invention that a substantially fluid state may beused. Compounds like water, CO₂ or ethylene can be maintained as asupercritical fluid. The residence time is generally in the range offrom 0.01 second to 20 minutes, preferably in the range of from 0.1second to 4 minutes, more preferably in the range of from 0.5 second to2 minutes, most preferably in the range of 1 second to 1 minute.“Residence time” is defined herein as the time the mixture comprisingthe monomers spends under the first condition for oligomerization.

[0027] A solvent or solvent mixture is not required, but may be usedoptionally as a medium, for the oligomerization reaction. They areherein collectively and interchangeably referred to as “solvent,”“solvents” or “solvent mixture.” A solvent selected for a particularoligomerization reaction should neither interfere with the desiredoligomerization reaction nor react substantially with the functionalgroup present either in any of the monomers or in the oligomer product.It is preferable that a solvent can be easily separated or removed fromthe reaction products by such methods as distillation, phase separation,or evaporation. If a catalyst, mediator, or initiator is used, it ispreferred to have a solvent in which the catalyst or initiator issoluble in a usable amount. A mediator is a compound which, while notbeing able to catalyze the reaction, may nonetheless influence thereaction in a certain desirable manner. Examples of a solvent suitablefor use in an oligomerization reaction include, but are not necessarilylimited to, ethylene, pentane, hexane, heptane, octane, benzene,toluene, xylene(s), carbon dioxide, water, methanol, ethanol,isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone,methyl formate, ethyl acetate, and mixtures thereof. Examples ofinitiators, if present, include hydrogen peroxide, alkylhydroperoxidesuch as t-butyl hydroperoxide and t-amyl hydroperoxide, dialkylperoxides such as di-t-butyl peroxide, peracids, peresters,percarbonates, persulfates, ketone peroxides such as methyl ethyl ketoneperoxide, oxygen, azo initiators and mixtures thereof.

[0028] In cases where the functional groups are generated by at leastone post-oligomerization reaction, such a post-oligomerization reactionis carried out under a functional-group-generation condition which isknown to those skilled in the art. Such post-oligomerization reactionsinclude, but are not necessarily limited to hydrolysis, esterification,trans-esterification and epoxide ringopening reaction. The reaction maybe carried out in a solvent and/or in the presence of a catalyst. Forexample, in a hydrolysis, esterification, or trans-esterificationreaction, an acid catalyst or a base catalyst is typically used.

[0029] The reaction between the functional group of the oligomer and thereactive moiety of a modifier is carried out under a second conditionwhich depends on the functional group, the reactive moiety, the solvent(if present), and other physical and chemical properties of the oligomerand the modifier. The second condition comprises a temperature in therange of from 0° C. to 450° C. and a residence time in the range of from0.1 second to 120 hours. Pressure is generally not a critical parameterunless the modifier has a relatively high vapor pressure at the reactiontemperature. Accordingly, a wide range of pressure may be used. Ambienttemperature is most convenient for most such reactions. If needed, apressure in the range of from 1 kPa (about 0.01 bar) to 35 MPa (350bars) maybe used. To the extent that such reactions conditions aredisclosed in U.S. Pat No. 4,059,616, U.S. Pat No. 4,133,793, and U.S.Pat No.4,208,313, they are incorporated herein by reference.

[0030] This reaction between a functional group and a reactive moietymay be conveniently carried out in air if there are no substantial sidereactions or byproduct productions. Sometimes air or oxygen need bepresent in order to allow certain inhibitors such as hydroquinone to beused effectively. Optionally, a different non-reactive atmosphere may beused, particularly if air may interfere with reaction and/or cause anyof the components to decompose or deteriorate. Examples of gases forproviding such non-reacting atmosphere include, but are not necessarilylimited to nitrogen, argon, helium or mixtures thereof. Gases likecarbon dioxide also may be used alone or in conjunction with thenon-reacting atmosphere described above if such gases do not interferewith the reaction and/or cause any of the components to decompose ordeteriorate.

[0031] Unlike prior art products, the oligomers prepared in accordancewith the process of the present invention are usually terminallyunsaturated. If desired, the unsaturated terminals may be subjected tofurther reactions such as hydrogenation, epoxidation, or a number ofother addition reactions known in the art.

[0032] A modifier suitable for the present invention depends on thenature of the functional group. They are described below in more detail.Generally, the modifier must have at least one reactive moiety whichwill react with the functional group. Another requirement of a suitablemodifier is that it must have a crosslinkable group selected from thegroup consisting of carbon-carbon double bond (C═C), anoxygen-containing heterocyclic group, and mixtures thereof, wherein thecrosslinkable group remains pendant or substantially unreacted after thereaction between the modifier and the oligomer through the reactivemoiety and the functional group respectively.

[0033] Examples of a reactive moiety in a suitable modifier include, butare not necessarily limited to C—OH [hydroxyalkyl group],—C(═O)OH,—C(═O)OR, —C(═O)X, oxygen-containing heterocyclic group and mixturesthereof. R is selected from a C₁ to C₁₅ alkyl group or an aryl group.Examples include, but are not necessarily limited to methyl, ethyl,n-propyl, n-butyl, 2-ethylhexyl, phenyl, and mixtures thereof. X isselected from the group consisting of chloride, bromide, and iodide.Examples of an oxygen-containing heterocyclic group include oxiranyl,oxetanyl and 1,3-dioxolanyl groups of the following formula:

[0034] R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸are independently selected fromthe group consisting of H and C₁—C₈ alkyl groups. H is preferred for allof the “R” groups. It is also preferred to have two of R¹, R² and R³ asH, and the other, CH₃.

[0035] Examples of a modifier include, but are not necessarily limitedto, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate,2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropylmethacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate,cinnamic acid, methylcinnamic acid, acrylic acid, methacrylic acid,crotonic acid, methyl acrylate, methyl methacrylate, methyl crotonate,ethyl acrylate, ethyl methacrylate, ethyl crotonate, n-propyl acrylate,n-propyl methacrylate, n-propyl crotonate, n-butyl acrylate, n-butylmethacrylate, n-butyl crotonate, 2-ethylhexyl acrylate, 2-ethylhexylmethacrylate, 2-ethylhexyl crotonate, acryloyl chloride, methacryloylchloride, crotonyl chloride, and mixtures thereof, provided that therespective modifies are chemically compatible with each other in themixtures.

[0036] The following reactions between the oligomer and the modifier arewithin the scope of the present invention whether the functional groupsare present in the monomer A prior to the oligomerization or they aregenerated post-oligomerization from either the “monomer A equivalent” orthe monomer B units incorporated in the oligomer backbone structure.

[0037] I. When the functional group is hydroxy (—OH) groups, thereactive moieties of the modifier are selected from the group consistingof ethylenically unsaturated carboxylic acids, esters of theethylenically unsaturated carboxylic acids, acyl halide derivatives ofthe ethylenically unsaturated carboxylic acids, and mixtures thereof.Examples of a monomer A in this group include, but are not necessarilylimited to allyl alcohol, 2-hydroxyethyl acrylate, 2-hydroxyethylmethacrylate, 2-hydroxyethyl crotonate, 3-hydroxypropyl acrylate,3-hydroxypropyl methacrylate, 3-hydroxypropyl crotonate, 4-hydroxybutylacrylate, 4-hydroxybutyl methacrylate, 4-hydroxybutyl crotonate andmixtures thereof. Examples of monomer A equivalent include allylacetate, allyl propionate, and vinyl acetate. Examples of a modifierinclude, but are not necessarily limited to, acrylic acid, methacrylicacid, crotonic acid, maleic acid, fumaric acid, itaconic acid,citraconic acid, cinnamic acid, methylcinnamic acid, methyl acrylate,methyl methacrylate, methyl crotonate, ethyl acrylate, ethylmethacrylate, ethyl crotonate, n-propyl acrylate, n-propyl methacrylate,n-propyl crotonate, i-propyl acrylate, i-propyl methacrylate, i-propylcrotonate, n-butyl acrylate, n-butyl methacrylate, n-butyl crotonate,2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl crotonateand mixtures thereof, acryloyl chloride, methacryloyl chloride, crotonylchloride, methacrylic anhydride and mixtures thereof.

[0038] II. When the functional group is selected from the groupconsisting of epoxide (oxiranyl) and carbon-carbon double bond; and themodifiers consist essentially of a compound selected from anethylenically unsaturated carboxylic acid or their mixtures, and anethylenically unsaturated alcohol or their mixtures. Examples of amonomer A in this group are 1,3-butadiene 1,2 epoxide, glycidylacrylate, glycidyl methacrylate, glycidyl crotonate,1-vinyl-4-cyclohexene epoxide, 1,3-butadiene, isoprene,1-vinyl-4-cyclohexene, norbornadiene, and mixtures thereof. Examples ofa modifier include acrylic acid, methacrylic acid, crotonic acid, maleicacid, fumaric acid, itaconic acid, citraconic acid, cinnamic acid,methylcinnamic acid and mixtures thereof. Other suitable modifiersinclude 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,2-hydroxyethyl crotonate, 3-hydroxypropyl acrylate, 3-hydroxypropylmethacrylate, 3-hydroxypropyl crotonate, 4-hydroxybutyl acrylate,4-hydroxybutyl methacrylate, 4-hydroxybutyl crotonate and mixturesthereof. Methylolacrylamide also may be used as a modifier.

[0039] III. When the functional group is selected from the groupconsisting of anhydride, alkoxysilyl, and mixtures thereof, the modifieris selected from the group consisting of hydroxyalkyl esters ofethylenically unsaturated carboxylic acids and mixtures thereof.Examples of the monomer A in this group include, but are not necessarilylimited to maleic anhydride, itaconic anhydride, citraconic anhydride,γ-methacryloxypropyltrimethoxysilane, vinyltriethoxysilane,vinyltrimethoxysilane, vinyltrichlorosilane, allyltriethoxysilane,allyltrichlorosilane, vinyl crotonate and mixtures thereof. Examples ofmodifiers include, but are not necessarily limited to 2-hydroxyethylacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl crotonate,3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxpropylcrotonate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate,4-hydroxybutyl crotonate, and mixtures thereof.

[0040] IV. When the functional group is selected from the groupconsisting of hydroxyl (COH), carboxyl (COOH), amino (NH₂), andsubstituted amino (NHR or NR′R″) groups, the reactive moiety of amodifier consists essentially of an oxiranyl group. Examples of apreferred monomer A is selected from the group consisting ofdimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, andmixtures thereof. Examples of such a modifier include glycidyl acrylate,glycidyl methacrylate and glycidyl crotonate.

[0041] V. When the functional group is selected from the groupconsisting of an anhydride group, the reactive moiety of a suitablemodifier may be an oxiranyl group. Examples of a monomer A includemaleic anhydride, citraconic anhydride, itaconic anhydride, and mixturesthereof Examples of a suitable modifier include glycidyl acrylate,glycidyl methacrylate, glycidyl crotonate, and mixtures thereof.

[0042] VI. When the functional group is selected from the groupconsisting of an aldehyde, a ketone group, the reactive moiety in asuitable modifier is preferred to contain a hydroxyalkyl group. Examplesof the monomer A include acrolein, methacrolein, methyl vinyl ketone,and mixtures thereof Examples of a suitable modifier include2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethylcrotonate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate,3-hydroxypropyl crotonate, 4-hydroxybutyl acrylate, 4-hydroxybutylmethacrylate, 4-hydroxybutyl crotonate and mixtures thereof.

[0043] VII. When the functional group is a vinyl group as part of anester, no reaction with a reactive moiety is needed when the curingmethod is selected from electromagnetic irradiations. Examples ofmonomer A include, but are not necessarily limited to vinyl acrylate,vinyl methacrylate, vinyl crotonate, and mixtures thereof. Examples ofmonomer B include, but are not necessarily limited to ethylene,propylene, C₄ to C₁₀ α-olefins, butadiene, isoprene, styrene,substituted styrene such as p-methylstyrene, vinyl ester, vinyl ether,vinyl silane such as vinyltrimethylsilane, vinyl halide, acrylic acid,methacrylic acid, crotonic acid, alkyl acrylate or methacrylate, orcrotonate ester such as methyl acrylate, methyl methacrylate, methylcrotonate, ethyl acrylate, ethyl methacrylate, ethyl crotonate, n-propylacrylate, n-propyl methacrylate, n-propyl crotonate, n-butyl acrylate,n-butyl methacrylate, n-butyl crotonate, and mixtures thereof.,acrylamide, methacrylamide, N-substituted acrylamide, N-substitutedmethacrylamide and mixtures.

[0044] VIII. When monomer A is selected from vinyl chloride, vinylbromide, vinyl acetate, vinyl benzoate, vinylidene halide (such aschloride or fluoride) and mixtures thereof, the modifier comprises ametal salt of an unsaturated acid or a mixture of such salts. Examplesof such unsaturated acids include acrylic acid, methacrylic acid,crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconicacid, cinnamic acid, methylcinnamic acid and mixtures thereof. The metal(ion) is selected from the group consisting of metals selected from theGroups IA(Li, Na, K, Rb, Cs), IIA (Be, Mg, Ca, Sr, Ba), IIIA(Al. Ga, In,Tl) and mixtures of the period table. (see inside front cover of CRCHandbook of Chemistry and Physics, 76th Ed. 1995-1996, D. R. Lide,Editor-in-Chief CRC Press, Inc. 1995) Examples of such a salt include,but are not necessarily limited to lithium acrylate, lithiummethacrylate, lithium crotonate, sodium acrylate, sodium methacrylate,sodium crotonate, potassium acrylate, potassium methacrylate, potassiumcrotonate, rubidium acrylate, rubidium methacrylate, rubidium crotonate,cesium acrylate, cesium methacrylate, cesium crotonate, magnesiumacrylate, magnesium methacrylate, magnesium crotonate, aluminumacrylate, aluminum methacrylate and mixtures thereof. It is preferred touse phase transfer catalysis (PTC) in this case to achieve reasonablereaction rates. PTC can be effected by choosing an appropriate phasetransfer catalyst(s). Depending on the catalyst selected, the amount ofa phase transfer catalyst used is, based on the total moles of themodifier present, in the range of from 0 mol% to 50 mol%, preferably inthe range of from 0.001 mol% to 25 mol%, most preferably in the range offrom 0.01 mol% to 20 mol%.

[0045] Typical phase transfer catalysts include, but are not limited to,quaternary ammonium, phosphonium, arsonium, antimonium, bismuthonium,and tertiary sulfonium salts, crown ethers. For the salts, examples ofsuitable counter ions include, but are not necessarily limited to,hydroxide, halide, sulfate, bisulfate, phosphate, nitrate, and mixturesthereof. Examples of such catalysts include tetra-n-butylammoniumbromide, tetra-n-butylammonium chloride, tetra-n-butylammonium iodide,tetra-n-butylammonium bisulfate, tetra-n-butylammonium hydroxide,tetraethylammonium bromide, tetramethylammonium bromide,tetra-n-propylammonium bromide, monomethyl, trioctylammonium chloride[Aliquat 336] benzyl triethylammonium bromide, hexyl triethylammoniumbromide, octyl triethylammonium bromide, cetyl trimethylammoniumbromide, tricaprylylmethylammonium bromide, phenyl trimethylammoniumbromide, tetraphenylphosphonium bromide, triphenylmethylphosphoniumbromide, tetrabutylphosphonium bromide, tetraphenylarsonium bromide,pyridyl-butyl bromide, cetylpyridinium bromide, dicyclohexano-18-crown-6ether; 18-crown-6 and mixtures thereof. A reference in the area is PhaseTransfer Catalysis: Fundamentals, Applications, and IndustrialPerspectives, by C. Starks, C. Liotta, and M. Halpern, Chapman & Hall,N.Y., (1994). “Aliquat” is a registered trademark of General Mill, Inc.

[0046] IX: When the functional group in monomer A is an epoxide(oxiranyl) group, examples of a monomer A include glycidyl acrylate,glycidyl methacrylate, glycidyl crotonate, monoglycidyl maleate,monoglycidyl fumarate, and mixtures thereof. Examples of monomer Binclude, but are not necessarily limited to, ethylene, butadiene,isoprene, styrene, p-methylstyrene, methyl acrylate, methylmethacrylate, methyl crotonate, ethyl acrylate, ethyl methacrylate,ethyl crotonate, n-propyl acrylate, n-propyl methacrylate, n-propylcrotonate, n-butyl acrylate, n-butyl methacrylate, n-butyl crotonate,2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexylcrotonate, a vinyl ester such as vinyl acetate, a vinyl ether such asvinyl ethyl ether, vinyl n-propyl ether, vinyl n-butyl ether, vinylsilane such as vinyltrimethylsilane and mixtures thereof. The curingmethod is selected from the group consisting of acid cure, base cure,generation of acid by an electromagnetic irradiation selected from thegroup consisting of ultraviolet, visible light, X-ray irradiation, and γirradiation and combinations thereof to produce a cured product from theradiation curable composition.

[0047] Preferred oligomer compositions (monomer A and monomer B) and thecorresponding modifiers include, but are not necessarily limited to,those listed in the following Table 1: TABLE 1 monomer A Group (monomerA equivalent)^(a) monomer B^(b) modifier^(c) II GA BA AA, MAA, or AOPAII GMA BA AA, MAA, or AOPA II GMA EA AA, MAA, or AOPA I HEA BA AA, MAA,or AOPA III MAN BE HEA or HEMA IV HEA EA ICEMA II IP BA AA II BD BA AAIV AA BA GMA III VTMO BA HEA or HEMA  I^(d) VOH (VAc) BA AA or AOPA IVHBA BA GMA or GA IV HBA MMA GMA or GA I HEA BA MA or MMA I HBA BA AA,MAA, or AOPA

[0048] It is also within the scope of the present invention that theoligomers, after reaction with the modifier, may be dispersed oremulsified in a solvent consisting essentially of water to form awaterborne formulation which can be used and cured, provided that thereis a reasonable chemical and physical stability of the composition insuch a waterborne formulation. It is generally required to have asurfactant in the formulation. Many surfactants known to those skilledin the art may be used, including but not limited to anionicsurfactants, cationic surfactants, amphoteric surfactants and nonionicsurfactants. Some specific examples include Triton X-100 and TritonX-200. (“Triton” is a registered trademark owned by Union CarbideChemicals & Plastics Technology Corporation.)

[0049] The terms “curable” and “crosslinkable” are used interchangeablyherein to mean that a pendant double bond or oxygen-containingheterocyclic group can be further reacted/crosslinked under a set ofsuitable conditions and in the presence of one parameter selected fromthe group consisting of a catalyst, an energy source, a free radicalsource, an acid, a base, or a combination thereof. The curablecomposition may be cured (crosslinked) by a number of methods. Examplesof such methods include, but are not necessarily limited toelectromagnetic irradiation such as UV irradiation(UV), visible lightirradiation(VIS), γ irradiation, and X-ray irradiation(X-ray), electronbeam irradiation (E-beam), chemical or thermal generation of freeradicals, electrochemical generation of free radicals, photochemicalgeneration of free radicals and combinations thereof. For E-beam and/orelectromagnetic irradiations such as UV/VIS irradiation as the curingmethod(s), the curable composition may further comprise one or morephotoinitiators as an additive(s) which function as free-radicalinitiator(s), cationic initiator(s), or anionic initiator(s). A generalreference for photo free-radical generations and photoinitiators can befound in Chapter 5 of “Photogeneration Of Reactive Species For UVCuring” by C. Roffey, John Wiley & Sons, NEW YORK, N.Y. (1997). To theextent the reference discloses various suitable photoinitiators and/orphoto free-radical generations, it is incorporated herein by reference.

[0050] Acids or electromagnetic irradiation (such as UV and/or VISirradiation) for generating acids or bases may be used for curing acomposition having oxygen-containing heterocyclic groups such asoxiranyl, oxetanyl or 1,3-dioxolanyl groups. E-beam, UV and/or VISirradiation(s) are three of the preferred curing methods.

[0051] The curable compositions, particularly may further comprise oneor more diluent monomers as another additive, with or without one ormore photoinitiators. Such a diluent monomer(s) may or may not be thesame as one or more of the monomers which are already incorporated intothe backbone of the oligomer(s). Many monomers or their mixtures used toform the oligomer(s) may serve the function as a “diluent monomer(s).” Adiluent monomer may serve to reduce viscosity, provide solvency, and/orprovide additional desired properties to the final cured product,particularly for producing an electromagnetic irradiation cured product.A general reference of such diluent monomers or sometimes referred to asreactive monomers in the curing composition can be found in Chapter 6 of“Photogeneration Of Reactive Species For UV Curing” by C. Roffey, JohnWiley & Sons, NEW YORK, N.Y. (1997).

[0052] Table 2 provides a simplified general guideline for selecting thevarious components: TABLE 2 Curing method Required^(a) Optional^(b) EB,X-ray or γ-ray — monomers UV or VIS photo initiators monomers (radical;photoacid; photobase) free radical free radical sources monomers(thermal or chemical) acid or base acid or base sources monomers

[0053] Generally, a UV source has a wavelength in the range of from 180nm to 400 nm. A visible light (VIS) source has a wavelength in the rangeof from 400 nm to 700 nm. Information regarding EB may be found inRadiation Curing In Polymer Science and Technology-Volume I, ed. J. P.Fouassier and J. F. Rabek, Elsevier Applied Science, New York, 1993Information regarding photoacids may be found in Radiation Curing InPolymer Science and Technology-Volume II, ed. J. P. Fouassier and J. F.Rabek, Elsevier Applied Science, New York, 1993 and in Prog. Polym.Sci.,Vol. 21, pp 1-45, 1996.

[0054] For all the reactions involved in the process discussed herein,it is understood that they can be carried out individually in acontinuous mode, a semi-continuous mode, a batch mode, a continuouslystirred tank reactor mode, or a combination thereof. The various stagesof the process may be carried out in the same reactor or differentreactors. It is preferred to carry out the oligomerization reaction in acontinuous mode. The reactor geometry and/or the residence time may beadjusted to provide different flow regimes for controlling the productyield, product composition and/or product properties. Such informationis available in many references. One such reference is U.S. Pat. No.5,710,227 (supra). Alternately, some of the reactions may be carried outsimultaneously in a continuous mode, a semi-continuous mode, a batchmode, a continuously stirred tank reactor mode, or a combinationthereof.

[0055] While it is generally preferred to recover the product from eachindividual reaction of the process prior to conducting the nextreaction, the present invention also will work with minimum or norecovery or no purification. For example, it is not required torecover/separate the oligomers prior to reacting with a modifier toproduce the curable compositions, or carrying out thepost-oligomerization generation of functional groups. In a case wherethe monomers and the modifier in the feed at the same time, there is noneed for any intermediate purification or separation. Typical recoveryor purification methods include, but not necessarily limited todistillation, extraction, filtration, centrifugation, sedimentation,solvent removal, residual monomer removal, residual modifier removal,catalyst removal and combinations thereof.

[0056] The present invention further relates to a curable compositionprepared in accordance with the disclosed process. In particular thecurable composition comprises of an oligomer having a Dp in the range offrom 3 to 100 which has reacted with a modifier after the oligomer isformed, wherein the oligomer is prepared from a monomer A and monomer B.The composition may further comprise a free monomer selected from any ofthe monomers disclosed herein. The free monomer may or may not be thesame as either the monomer A or the monomer B in the oligomer.

[0057] Preferably, the curable composition consists essentially of (a)an oligomer having a Dp in the range of from 3 to 100 which has reactedwith a modifier after the oligomer is formed, wherein the oligomer isprepared from a monomer A and monomer B, (b) a free monomer selectedfrom any of the monomers disclosed herein, (c) an initiator,. The freemonomer may or may not be the same as either the monomer A or themonomer B in the oligomer.

[0058] The following examples are intended for illustration purposesonly. They should not be interpreted to limit the scope or spirit of thepresent invention which is solely defined by the claims and thespecification disclosed herein.

EXAMPLE I Oligomerization

[0059] An oligomer of the present invention may be prepared inaccordance with the following procedure.

[0060] A 10-foot (3.3 meters) long section of stainless tubing having aninner diameter of one-sixteenth inch (1.6 mm) and wall thickness of0.050 inch (1.27 mm) was connected at one end to a high pressure pump(Hewlett Packard Model HP 1050 TI) and at the other end to aback-pressure control device. Between the two ends, the section oftubing was coiled about a torus-shaped metal mandrel. The mandrel wassituated above a primary coil of a transformer so that the coils oftubing and the mandrel functioned as secondary coils of the transformer.The coils of tubing were further equipped with one end of a temperatureprobe. The other end of the temperature probe was connected to atemperature controlling device. The temperature controlling deviceregulated the current supplied to the primary coil of the transformerwhich had the effect of regulating the heat of inductance imparted tothe coiled steel tubing.

[0061] A mixture of a monomer A and a monomer B (a few specific examplesare shown below in the Table 3) was used in the oligomer synthesisreaction. The mixture may further comprise an initiator and optionally asolvent. Nitrogen was bubbled through the mixture while stirring. If asolvent was not used, the initiator and monomers were separately fedinto the reactor.

[0062] In a typical experiment, a suitable solvent was pumped into andthrough the tubing via the high pressure pump at a certain preset ratein the range of from about 0.05 to about 10 milliliters per minute(ml/min). The pressure was maintained at a level of from 20 MPa (200bars) to 35 MPa (350 bars). Electric current was supplied to the primarycoil of the transformer to increase the temperature within the tubing tothe desired oligomerization temperature. The current was then adjustedto maintain that temperature for the oligomerization reaction. Afterabout 15 minutes, the solvent being pumped through the tubing wasreplaced by the reaction mixture which as continuously pumped throughthe tubing at the same preset rate while maintaining the desiredtemperature and pressure. After an amount of time has elapsed for thesolvent to be totally replaced from the inside of the tubing, theeffluent from the back-pressure control device was collected as theproduct. After the supplies of the mixture, or individual monomers, wereused up, a solvent was pumped through the tubing at the same presentrate, temperature, and pressure. Any solvent and/or residual monomerswere removed from the product on a rotary evaporator.

[0063] The products in Table 3 were analyzed by various analyticalmethodsmolecular weights by gel permeation chromatography (GPC);structure and co-monomer ratio by proton and carbon NMR spectroscopies;and end-groups by NMR or matrix-assisted laser desorption massspectrometry (MALDI-MS). TABLE 3 Oligomer# Monomer A* Monomer B* Mw Mn A2.6 HBA 5.6 BA 2130 1091 B 3.2 HEA 5.4 BA 2302 1064 C 2.5 GA 6.0 BA 22451083 D 2.5 GMA 5.4 BA 2250 1144 E 2.5 HEA 6.0 BA 5350 2384

EXAMPLE II Reaction of a Modifier with an Oligomer

[0064] The equipment used was a 250 ml three-neck round bottom flaskoutfitted with a reflux condenser, an overhead stirrer, a gas inlet tubeand a thermocouple. The flask was charged with (a) 137.06 grams of anoligomer having a composition of 38:62 (mole %) of GMA (glycidylmethacrylate, monomer A) to EA (ethyl acrylate, monomer B), a Dp of 6.5and 23,000 ppm residual GMA, (b) 40.0 grams acrylic acid, (c) 0.2 gramsof Cordova Accelerator AMC-2 (chromium 2-ethylhexanoate), and (d) 0.26grams of a 10%(weight) solution of Actrene [registered trademark ofExxon Corporation] in propylene glycol methyl ethyl ether.

[0065] The mixture in the flask was stirred and heated under drynitrogen to 90° C. for 6 hours. No GMA residuals were detected afterthis period. The reflux condenser was then replaced with a distillationhead and any unreacted AA was removed by distillation under reducedpressure with a house vacuum.

[0066] Other examples where the modifier was acrylic acid (AA) were:TABLE 4 Product Monomer A* Monomer B* Modifier Mw Mn A2 2.6 HBA 5.6 BA2.5 AA 3567 1350 B2 3.2 HEA 5.4 BA 3.1 AA 5124 1740 C2 2.5 GA 6.0 BA 2.5AA 2719 1385 D2 2.5 GMA 5.4 BA 2.5 AA 2614 1279

EXAMPLE III Reaction of a Modifier with an Oligomer

[0067] The equipment used was a 100 ml three-neck round bottom flaskoutfitted with a reflux condenser, an magnetic stirring bar, an airinlet tube and a thermocouple. The flask was charged with 41.1 grams ofan oligomer having a composition of 20:80 (mole %) of AA (acrylic acid,monomer A) to BA (n-butyl acrylate, monomer B) and Mn of 1204. Withstirring, the flask and the oligomer were heated to about 100° C. undera dry air purge over a period of 15 minutes. The mixture was cooled toroom temperature over a 30 minute period under a dry air purge, followedby addition of 16.31 grams of GMA, 20 grams ethyl acetate and 0.06 gramsof Cordova Accelerator AMC-2 (chromium 2-ethylhexanoate). While stirringunder a dry air purge, the mixture was heated to about 85° C. for fivehours. It was then cooled to room temperature. Residual GMA was found tobe 2300 ppm.

[0068] A portion of 0.25 g of 2-(ethylamino)ethanol was added to theflask and the mixture was heated to 65° C. over 20 minutes, cooled toroom temperature and let stand for 4 days. Residual GMA was found to be150 ppm. To this were added 20.0 grams acetic acid and 10.0 grams ofethyl acetate. The mixture was heated to 80° C. for 8 hours. No residualGMA was detected after this period. The reflux condenser was thenreplaced with a distillation head. Residual acetic acid and ethylacetate were distilled off under reduced pressure to produce the desiredproduct.

EXAMPLE IV Reaction of Modifier with Oligomer

[0069] The equipment used was a 250 ml pear-shaped flask outfitted witha magnetic stirring bar and a drying tube. The flask was charged with(a) 25 grams of an oligomer having a composition of 1:2 (mole ratio) ofHEA (monomer A) to EA (monomer B); (b) 50 ml THF; and (c) 12.2 grams ofisocyanatoethyl methacrylate (ICEMA). A 0.05 g dibutyltin dilauratecatalyst was added to this mixture at 25° C. The mixture was thenstirred at 25° C. for two days. An additional 0.45 g of the samecatalyst was added and the mixture was heated in an oil bath to 50° C.for 4 days. At this time, it was determined that all the isocyanategroups have been converted to urethane groups. The product wasconcentrated by removing volatiles with a rotary evaporator. The productwas characterized by Fourier transform infrared spectroscopy (FTIR);C-13 nuclear magnetic resonance (NMR); 2-dimensional NMR, and MALDI-MS.The glass transition temperature (Tg) and viscosity of the liquidproduct were −73° C. and 16,000 MPa-sec (cps, Brookfield viscometer at25° C.) respectively.

EXAMPLE V Reaction of Modifier with Oligomer

[0070] The following are other examples. Reactions 1-4 were carried outneat, and reactions 5-10, in refluxing toluene with azeotropic removalof water. The reaction mixture also contained inhibitors: 1.4-hydroxy-2,2,6,6,-tetramethylpiperidinyloxy (HTEMPO, 500 ppm); 2:butylhydroxytoluene (BHT, 1000 ppm)/air; 3: HTEMPO (500 ppm); 4: HTEMPO(500 ppm); 5: BHT (1000 ppm)/air; 6: hydroquinone(1000 ppm) /air; 7:HTEMPO (500 ppm); 8: HTEMPO (500 ppm); 9: HTEMPO (500 ppm); 10: HTEMPO(500 ppm). TABLE 5 No. oligomer^(a) modifier^(b) catalyst^(c) time (h)temp (° C.) conv^(d) conv^(e) Mw/Mn 1 P1 AA Cr 1.5 100 97% 96% 4015/15172 P1 AA Cr 1.5 100 91% 95% 4075/1494 3 P1 AA Cr 1.5 100 100%  97%2884/1466 4 P1 AA Cr 2.5 100 98% 94% 2719/1385 5 P2 AA MSA^(f) 3.5 g 97%h 3600/1515 6 P3 AA MSA^(f) 6.5 g 93-100% h 3728/1148 7 P2 AA AM 2.5 g88 h 4217/1285 8 P2 AA AM 2.5 g 93 h 5644/1760 9 P2 AA AM 2.5 g 93 h4734/1383 10 P2 AA AM 2.5 g 100  h 3294/1291

[0071] These examples showed that oligomers could be reacted withmodifiers to form products of this invention.

EXAMPLE VI UV Curing

[0072] An oligomer, either neat, or formulated, was applied to thesurface of a substrate by using a wet film applicator to form a filmwith 2 mil (5.1×10⁻³ cm) thickness. The film applicator used was anEight-Path Wet Film Applicator from Paul N. Gardner Company, Inc.Substrates include glass, aluminum, and cold rolled steel.

[0073] The coated surfaces were then cured, in air or nitrogen, with anRPC Model 1202 UV processor equipped with two 200 watts/inch (80watts/cm) medium pressure mercury arc lamps at a belt speed of 20 to 100feet (6 to 30 meters) per minute. The table below represents the typicalenergy/area at various belt speeds, measured by using a CompactRadiometer (UV Process Supply Inc.). TABLE 6 Speed (feet/min;[meters/min]) Energy/Area (wJoule/cm²) 20 [6]  2400 40 [12] 1200 60 [18] 780 80 [24]  620 100 [30]   500

[0074] The following Table 7 shows curing results obtained with neatproduct in the presence of 2 wt% Darocure 1173 obtained from CibaSpecialty Chemicals. TABLE 7 Swell Soluble Cure Conditions ProductRatio^(a) Fraction^(b) (%) no of passes/speed/atmosphere A2 3.3 35 3/50ft/min/air B2 2.1 15 4/50 ft/min/nitrogen B2 2.0 13 1/20 ft/min/nitrogenB2 1.7 5 2/20 ft/mm/nitrogen C2 1.6 9 6/50 ft/min/nitrogen D2 1.8 9 6/50ft/min/nitrogen E2 1.1 0 3/50 ft/min/nitrogen

[0075] The following Table 8 shows curing results with product B2 in thepresence of different amounts of a monomer TMPTA (and 2 wt% Darocure1173 obtained from Ciba Specialty Chemicals). TABLE 8 B2 TMPTA SwellSoluble Cure Conditions* wt % wt % Ratio Fraction (%) no of passes/speed100 0 2.0 13 1/20 ft/mm 75 25 1.2 3 1/20 ft/mm 50 50 1.1 0 1/20 ft/min

[0076] These examples showed that curable compositions prepared inaccordance with the present invention could be cured under a variety ofconditions.

It is claimed:
 1. A process of preparing a curable compositioncomprising: (a) forming an oligomer having a Dp in the range of from 3to 100 from oligomerization of a mixture which comprises a monomer A anda monomer B under a first condition, wherein the monomer A has at leastone functional group which either is generated after the oligomerizationor is present in the monomer A before the oligomerization and remainssubstantially unreacted during the oligomerization; the oligomer has afirst number of monomer units incorporated into its backbone; andwherein the first condition comprises a temperature in the range of from150° C. to 650° C., a pressure in the range of from 3 MPa to 35 MPawhich is sufficient to maintain the mixture in a fluid state and aresidence time at the temperature and the pressure in the range of from0.1 second to 4 minutes; and (b) reacting a modifier having at least onereactive moiety with the oligomer through a reaction under a secondcondition between the reactive moiety of the modifier and the functionalgroup of the monomer A incorporated into the oligomer to produce thecurable composition, wherein the modifier further comprises a curablegroup selected from the group consisting of a carbon-carbon double bond,an oxygen-containing heterocyclic group and mixtures thereof, and thecurable group remains pendant in the curable composition andcrosslinkable after the reaction.
 2. The process of claim 1, whereinsaid monomer B is selected from the group consisting of ethylene,propylene, C₄ to C₁₀ α-olefins, butadiene, isoprene, styrene,substituted styrene, vinyl ester, vinyl ether, vinyl silane, vinylhalide, acrylic acid, methacrylic acid, crotonic acid, alkyl acrylateester, alkyl methacrylate ester, alkyl crotonate ester, acrylamide,methacrylamide, N-subsituted acrylamide, N-substituted methacrylamideand mixtures thereof.
 3. The process of claim 1, wherein the functionalgroup is selected from the group consisting of a hydroxyl group, acarboxylic acid group, a halide, an oxiranyl group, an anhydride group,an ester, an alkoxysilyl group, and a carbon-carbon double bond.
 4. Theprocess of claim 2, wherein the monomer B is selected from the groupconsisting of vinyl acetate vinyl benzoate, methyl acrylate, ethylacrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate,sec-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethylmethacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butylmethacrylate, sec-butyl methacrylate, 2-ethylhexyl methacrylate,2-ethylhexyl crotonate, N,N-dimethylacrylamide, N,N-diethylacrylamide,N,N-dimethylacrylamide, N,N-diethylacrylamide,N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, vinyl chloride,vinyl bromide, vinyl ethyl ether, vinyl n-propyl ether, vinyl n-butylether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, 2-chloroethylvinyl ether, vinyltrimethylsilane and mixtures thereof.
 5. The processof claim 1, wherein the monomer A is selected from the group consistingof allyl alcohol, allyl acetate, allyl propionate, allyl acrylate, allylmethacrylate, allyl crotonate, vinyl acrylate, vinyl methacrylate, vinylcrotonate, 1,3-butadiene, isoprene, glycidyl methacrylate, glycidylacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate,4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropylmethacrylate, 4-hydroxybutyl methacrylate, maleic anhydride, itaconicanhydride, citraconic anhydride, vinyltrimethoxysilane,γ-methacryloxypropyltrimethoxysilane vinyltriethoxysilane,vinyltrichlorosilane, allyltriethoxysilane, allyltrichlorosilane, andmixtures thereof; and the monomer B is selected from the groupconsisting of acrylic acid, methacrylic acid, crotonic acid, maleicacid, fumaric acid, itaconic acid, citraconic acid, cinnamic acid,methylcinnamic acid, methyl acrylate, methyl methacrylate, ethylacrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate,i-propyl acrylate, i-propyl methacrylate, n-butyl acrylate, n-butylmethacrylate, sec-butyl acrylate, sec-butyl methacrylate and mixturesthereof.
 6. The process of claim 1, wherein the modifier is selectedfrom the group consisting of an ethylenically unsaturated acid, anethylenically unsaturated ester and mixtures thereof, and the functionalgroup consists essentially of a hydroxyl group or an ester group.
 7. Theprocess of claim 1, wherein the modifier is selected from the groupconsisting of an ethylenically unsaturated carboxylic acid and thefunctional group of the monomer A is selected from the group consistingof a hydroxyl, an oxiranyl, a carbon-carbon double bond, and mixturesthereof.
 8. The process of claim 1, wherein the modifier is selectedfrom the group consisting of a hydroxyalkyl ester of an ethylenicallyunsaturated carboxylic acid and mixtures thereof, and the functionalgroup of the monomer A is selected from the group consisting of ananhydride, an alkoxysilyl, and mixtures thereof.
 9. The process of claim1 wherein the modifier is selected from the group consisting of acrylicacid, methacrylic acid, crotonic acid, methyl acrylate, methylmethacrylate, methyl crotonate, ethyl acrylate, ethyl methacrylate,ethyl crotonate, n-propyl acrylate, n-propyl methacrylate, n-propylcrotonate, i-propyl acrylate, i-propyl methacrylate, i-propyl crotonate,n-butyl acrylate, n-butyl methacrylate, n-butyl crotonate, and mixturesthereof, acryloyl chloride, methacryloyl chloride, crotonyl chloride,and mixtures thereof; and the monomer A is selected from the groupconsisting of allyl alcohol, allyl acetate, allyl propionate,2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethylcrotonate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate,3-hydroxypropyl crotonate, 4-hydroxybutyl acrylate, 4-hydroxybutylmethacrylate, 4-hydroxybutyl crotonate and mixtures thereof.
 10. Theprocess of claim 1 wherein the modifier is selected from the groupconsisting of acrylic acid, methacrylic acid, crotonic acid, maleicacid, fumaric acid, itaconic acid, citraconic acid, cinnamic acid,methylcinnamic acid and mixtures thereof; and the monomer A is selectedfrom the group consisting of glycidyl acrylate, glycidyl methacrylate,4-vinyl-cyclohexene-1,2 epoxide, butadiene, isoprene,1-vinyl-4-cyclohexene, norbornadiene, and mixtures thereof.
 11. Theprocess of claim 1 wherein the modifier is selected from the groupconsisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,2-hydroxyethyl crotonate, 3-hydroxypropyl acrylate, 3-hydroxypropylmethacrylate, 3-hydroxypropyl crotonate, 4-hydroxybutyl acrylate,4-hydroxybutyl methacrylate, 4-hydroxybutyl crotonate, and mixtures of;and the monomer A is selected from the group consisting of maleicanhydride, itaconic anhydride, citraconic anhydride,vinyltrichlorosilane, vinyltrimethoxysilane, vinyl crotonate andmixtures thereof.
 12. The process of claim 1, wherein the monomer A isselected from the group consisting of vinyl chloride, vinyl bromide,vinyl acetate, vinyl benzoate, vinylidene chloride, vinylidene fluorideand mixtures thereof and the modifier comprises a metal salt of anunsaturated acid wherein the metal is selected from the group consistingof Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Al, Ga, In and mixturesthereof, and the unsaturated acid is selected from the group consistingof acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaricacid, itaconic acid, citraconic acid, cinnamic acid, methylcinnamic aicdand mixtures thereof, and wherein the second conditions furthercomprises addition in an amount of from 0 mol% to 50 mol% of a phasetransfer catalyst based on moles of the modifier.
 13. The process claim1, wherein a second number of the functional group is produced after theoligomerization, and wherein a ratio of the second number of thefunctional group to the first number of monomer units incorporated intothe backbone of the oligomer is in the range of from 1:100 to 1:1. 14.The process of claim 1, wherein the functional group is present in themonomer A and remains substantially unreacted during theoligomerization, and wherein a molar ratio of the monomer A to themonomer B incorporated into the oligomer is in the range of from 1:40 to40:1.
 15. The process of claim 1, wherein the monomer B comprises ethyl4,4,4-trifluorocrotonate.
 16. The process of claim 2, wherein the vinylether is selected from the group consisting of ethyl vinyl ether,n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether,2-ethylhexylvinyl vinyl ether, 2-chloroethyl vinyl ether and mixturesthereof and the vinyl silane comprises vinyltrimethylsilane.
 17. Theprocess of claim 1 further comprising curing the curable composition bya method selected from the group consisting of chemical generation offree radicals, electrochemical generation of free radicals,photochemical generation of free radicals, electron beam,electromagnetic irradiation selected from the group consisting ofultraviolet, visible light, X-ray irradiation, and γ irradiation andcombinations thereof to produce a cured product from the radiationcurable composition.
 18. The process of claim 17, wherein the method isselected from the group consisting of ultraviolet, visible light,electron beam and combinations thereof, and the curable compositionfurther comprises an additive selected from the group consisting of oneor more photoinitiators, one or more diluent monomers and mixturesthereof.
 19. A process of preparing an electromagnetic irradiationcurable composition comprising: (a) forming an oligomer fromoligomerization of a mixture which comprises a monomer A and a monomerB, wherein the monomer A has at least one functional group which eitheris generated after the oligomerization or is present in the monomer Abefore the oligomerization and remains substantially unreacted duringthe oligomerization; the monomer B is selected from the group consistingof acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate,ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propylmethacrylate, i-propyl acrylate, i-propyl methacrylate, n-butylacrylate, n-butyl methacrylate, sec-butyl acrylate, sec-butylmethacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate andmixtures thereof; and the oligomer is terminally unsaturated; (b)producing the electromagnetic irradiation curable composition byreacting a modifier having at least one reactive moiety with theoligomer through a reaction between the reactive moiety of the modifierand the functional group of the monomer A which has been incorporatedinto the oligomer, wherein the modifier further comprises acarbon-carbon double bond which remains pendant in the electromagneticirradiation curable composition and crosslinkable with irradiation afterthe reaction; (c) recovering the electromagnetic irradiation curablecomposition; and (d) subjecting the electromagnetic irradiation curablecomposition to an electromagnetic irradiation to produce anelectromagnetic irradiation cured product.
 20. An electromagneticirradiation curable composition c omprising an oligomer having pendantelectromagnetic irradiation crosslinkable carbon-carbon double bonds,wherein the oligomer has a Dp in the range of from 3 to 100 and isprepared by an oligomerization a mixture which comprises a monomer A anda monomer B, wherein the monomer A having at least one functional groupwhich remains substantially unreacted during the oligomerization and themonomer B is selected from the group consisting of acrylic a cid,methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate,ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, i-propylacrylate, i-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate,sec-butyl acrylate, sec-butyl methacrylate, 2-ethylhexyl acrylate,2-ethylhexyl methacrylate an d mixtures thereof, and producing theelectromagnetic irradiation curable composition by reacting a modifierhaving at least one reactive moiety with the oligomer through a reactionbetween the reactive moiety of the modifier and the functional group ofthe monomer A which has been incorporated into the oligomer, wherein themodifier further comprises a carbon-carbon double bond which remainspendant in the electromagnetic irradiation curable composition andcrosslinkable with electromagnetic irradiation after the reaction. 21.The electromagnetic irradiation curable composition of claim 19 or 20further comprising an additive selected from the group consisting of oneor more photoinitiators, one or more diluent monomers and mixturesthereof.
 22. The curable composition of claims 1 through 18 isemulsified in a solvent consisting essentially of water in the presenceof a surfactant to form a waterborne formulation.
 23. A method of usingof the curable composition of claims 1 through 18 for coating, film,paint, marking, adhesive, binder, ink and combinations thereof.
 24. Amethod of using of the waterborne formulation of claim 22 for coating,film, paint, marking, adhesive, binder, ink and combinations thereof.25. A process of producing an electromagnetic irradiation curablecomposition comprising forming an oligomer having a Dp in the range offrom 3 to 100 from an oligomerization of a mixture which comprises amonomer A and a monomer B under a first condition, wherein the monomer Ais selected from the group consisting of vinyl acrylate, vinylmethacrylate, vinyl crotonate, and mixtures thereof; the monomer B isselected from the group consisting of ethylene, propylene, C₄ toC₁₀-αolefins, butadiene, isoprene, styrene, substituted styrene, vinylester, vinyl ether, vinyl silane, vinyl halide, acrylic acid,methacrylic acid, crotonic acid, alkyl acrylate ester, alkylmethacrylate ester, alkyl crotonate ester, acrylamide, methacrylamide,N-substituted acrylamide, N-substituted methacrylamide and mixturesthereof; and wherein the first condition comprises a temperature in therange of from 150° C. to 650° C., a pressure in the range of from 3MPato 35MPa which is sufficient to maintain the mixture in a fluid state,and a residence time at the temperature and the pressure in the range offrom 0.1 second to 4 minutes.
 26. A process of preparing a curablecomposition comprising forming an oligomer having a Dp in the range offrom 3 to 100 from oligomerization of a mixture which comprises amonomer A and a monomer B under a first condition, wherein the monomer Ahas at least one oxiranyl group which either is generated after theoligomerization or is present in the monomer A before theoligomerization and remains substantially unreacted during theoligomerization; the oligomer has a first number of monomer unitsincorporated into its backbone; and wherein the first conditioncomprises a temperature in the range of from 150° C. to 650° C., apressure in the range of from 3 MPa to 35 MPa which is sufficient tomaintain the mixture in a fluid state and a residence time at thetemperature and the pressure in the range of from 0.1 second to 4minutes.
 27. The process of claim 26, wherein the monomer B is selectedfrom the group consisting of ethylene, butadiene, isoprene, styrene,p-methylstyrene, methyl acrylate, methyl methacrylate, methyl crotonate,ethyl acrylate, ethyl methacrylate, ethyl crotonate, n-propyl acrylate,n-propyl methacrylate, n-propyl crotonate, n-butyl acrylate, n-butylmethacrylate, n-butyl crotonate, 2-ethylhexyl acrylate, 2-ethylhexylmethacrylate, 2-ethylhexyl crotonate, vinyl acetate, vinyl ethyl ether,vinyl n-propyl ether, vinyl n-butyl ether, vinyltrimethylsilane andmixtures thereof
 28. The process of claim 26 or 27 further comprisingcuring the curable composition by a method selected from the groupconsisting of acid cure, base cure, generation of acid by anelectromagnetic irradiation selected from the group consisting ofultraviolet, visible light, X-ray irradiation, and γ irradiation andcombinations thereof to produce a cured product from the radiationcurable composition.
 29. The electromagnetic irradiation curablecomposition of claim 19 or 20 is emulsified in a solvent consistingessentially of water in the presence of a surfactant to form awaterborne formulation.
 30. A method of using of the electromagneticirradiation curable composition of claim 29 for coating, film, paint,marking, adhesive, binder, ink and combinations thereof.